Kish S.J.,Center for Addiction and Mental Health |
Fitzmaurice P.S.,ESR Institute of Environmental Science and Research |
Chang L.J.,Center for Addiction and Mental Health |
Furukawa Y.,Movement Disorder Research Laboratory |
Tong J.,Center for Addiction and Mental Health
Journal of Psychopharmacology | Year: 2010
Evidence that the widely used methamphetamine analog MDMA (3,4-methylenedioxymethamphetamine, ecstasy) might damage brain serotonin neurones in humans is derived from imaging investigations showing variably decreased binding of radioligands to the serotonin transporter (SERT), a marker of serotonin neurones. However, in humans, it is not known whether low SERT binding reflects actual loss of SERT protein itself. As this question can only be answered in post-mortem brain, we measured protein levels of SERT and that of the rate-limiting serotonin-synthesizing enzyme tryptophan hydroxylase (TPH) in autopsied brain of a high-dose MDMA user. As compared with control values, SERT protein levels were markedly (-48% to -58%) reduced in striatum (caudate, putamen) and occipital cortex and less affected (-25%) in frontal and temporal cortices, whereas TPH protein was severely decreased in caudate and putamen (-68% and -95%, respectively). The magnitude of the striatal SERT protein reduction was greater than the SERT binding decrease typically reported in imaging studies. Although acknowledging limitations of a case study, these findings extend imaging data based on SERT binding and suggest that high-dose MDMA exposure could cause loss of two key protein markers of brain serotonin neurones, a finding compatible with either physical damage to serotonin neurones or downregulation of components therein. © 2010 British Association for Psychopharmacology.
Zuo H.,Sichuan University |
Xie Z.,Sichuan University |
Ding X.,Sichuan University |
Zhang W.,Sichuan University |
And 5 more authors.
Quality Assurance and Safety of Crops and Foods | Year: 2011
Introduction: Salmonella, Shigella and Escherichia coli O157: H7 are major foodborne pathogens that cause gastrointestinal diseases worldwide. Apart from food contamination, fecal pollution has been consistently associated with the transmission of these pathogens, and their rapid detection in food and stools is of significance for food safety. However, a variety of factors associated with these complex samples can decrease the sensitivity and specificity of molecular-based methods for detection of these pathogens. Objectives: The aim of this study was to develop a DNA-based method for the simultaneous detection of E. coli O157: H7, Salmonella and Shigella in stool and food samples. Methods: In this study, a novel magnetic capture-multiplex polymerase chain reaction (PCR) assay was developed and its potential to detect the target pathogens in stool and food samples (including chicken, cucumbers and cooked rice) was tested. Results: The results showed that the magnetic particles (MPs) used in the study had a high capacity for bacterial adsorption. The pretreatment protocol, which included the pathogen concentration by MPs, was developed and the sensitivity of the assay was approximately 10° colony-forming unit (CFU)g -1 in food and 1-10CFUs per stool sample, following an enrichment step. The assay could be completed within 12h, and was comparable in performance with conventional culture methods, which require several days to complete. Conclusion: The assay combines MP-based magnetic capture with multiplex PCR, and offers an efficient, rapid, sensitive and inexpensive alternative for the routine detection of foodborne pathogenic bacteria. © 2011 Blackwell Publishing Ltd.
Simons J.L.,ESR Institute of Environmental Science and Research |
Gamblin A.,ESR Institute of Environmental Science and Research |
Gamblin A.,University of Auckland |
Arnold L.,ESR Institute of Environmental Science and Research |
And 2 more authors.
Forensic Science International: Genetics Supplement Series | Year: 2013
The examination of sexual assault evidence frequently involves the analysis of samples that comprise mixtures of male and female cells. Separating male and female cells benefits analysis as the results are more likely to be simplified into profiles from single contributors. Some separation methods have focussed on separation of sperm from epithelial cells, but samples without sperm also require separation (vasectomised males, licked skin, etc.). X/Y chromosome FISH labelling when combined with laser micro-dissection (LMD) is a reliable method to separate male and female epithelial cells, but has mostly been combined with increased cycle PCR to create DNA profiles, limiting its use in many forensic laboratories. This study aimed to determine the limits of cell numbers collected by LMD for standard 28-cycle DNA profiling, and to test the effects, if any, on stochastic variation normally caused by sampling effects. Male and female epithelial cells were stained using the Vysis CEP X/Y DNA Probe kits, and collected using a Leica LMD6000. DNA was extracted and amplified by the ESR in-house one-tube method, using standard 28-cycle PCR with the AmpFISTR Identifiler™ (Applied Biosystems) multiplex kit. Full IdentifilerTM DNA profiles were produced using standard 28-cycle PCR, and partial profiles suitable for submission were produced from even relatively low numbers of cells collected. Profiling results were compared with low-copy number PCR on low numbers of cells stained and collected in the same manner, and the observed effects on heterozygote balance are discussed. © 2013 Elsevier Ireland Ltd.
Tong J.,Research Imaging Center |
Tong J.,Addiction Imaging Research Group |
Fitzmaurice P.,ESR Institute of Environmental Science and Research |
Furukawa Y.,Juntendo University |
And 7 more authors.
Neurobiology of Disease | Year: 2014
Animal data show that high doses of the stimulant drug methamphetamine can damage brain dopamine neurones; however, it is still uncertain whether methamphetamine, at any dose, is neurotoxic to human brain.Since gliosis is typically associated with brain damage and is observed in animal models of methamphetamine exposure, we measured protein levels (intact protein and fragments, if any) of markers of microgliosis (glucose transporter-5, human leukocyte antigens HLA-DRα [TAL.1B5] and HLA-DR/DQ/DPβ [CR3/43]) and astrogliosis (glial fibrillary acidic protein, vimentin, and heat shock protein-27) in homogenates of autopsied brain of chronic methamphetamine users (n. = 20) and matched controls (n. = 23). Intact protein levels of all markers were, as expected, elevated (+. 28%-1270%, P<. 0.05) in putamen of patients with the neurodegenerative disorder multiple system atrophy (as a positive control) as were concentrations of fragments of glial fibrillary acidic protein, vimentin and heat shock protein-27 (+. 170%-4700%, P<. 0.005). In contrast, intact protein concentrations of the markers were normal in dopamine-rich striatum (caudate, putamen) and in the frontal cortex of the drug users. However, striatal levels of cleaved vimentin and heat shock protein-27 were increased (by 98%-211%, P<. 0.05), with positive correlations (r. = 0.41-0.60) observed between concentrations of truncated heat shock protein-27 and extent of dopamine loss (P= 0.006) and levels of lipid peroxidation products 4-hydroxynonenal (P= 0.046) and malondialdehyde (P= 0.11).Our failure to detect increased intact protein levels of commonly used markers of microgliosis and astrogliosis could be explained by exposure to methamphetamine insufficient to cause a toxic process associated with overt gliosis; however, about half of the subjects had died of drug intoxication suggesting that "high" drug doses might have been used. Alternatively, drug tolerance to toxic effects might have occurred in the subjects, who were all chronic methamphetamine users. Nevertheless, the finding of above-normal levels of striatal vimentin and heat shock protein-27 fragments (which constituted 10-28% of the intact protein), for which changes in the latter correlated with those of several markers possibly suggestive of damage, does suggest that some astrocytic "disturbance" had occurred, which might in principle be related to methamphetamine neurotoxicity or to a neuroplastic remodeling process. Taken together, our neurochemical findings do not provide strong evidence for either marked microgliosis or astrogliosis in at least a subgroup of human recreational methamphetamine users who used the drug chronically and shortly before death. However, a logistically more difficult quantitative histopathological study is needed to confirm whether glial changes occur or do not occur in brain of human methamphetamine (and amphetamine) users. © 2014 Elsevier Inc.